Variability of the diameter and taper of size #30, 0.04 nickel-titanium rotary files.

This investigation examined the variability of tip diameter (D0) and taper measurements among four different brands of #30, 0.04 nickel-titanium (NiTi) rotary files (n=15/brand). With all brands, the mean percent D0 difference from the manufacturer's reported (nominal) diameter (Profile GT, 1.73+/-2.03%; Endo Sequence, 3.38+/-3.91%; K3, 4.56+/-2.36%; Profile, 6.13+/-4.07%) indicated that files tended to be larger than the nominal diameter. A 1-factor ANOVA and Tukey's post hoc test revealed a statistically significant difference (p<or=0.05) between Profile GT (smallest difference from nominal) and Profile (largest difference). The ANOVA also indicated no significant effect (p>0.05) of brand on the mean percent difference of the measured taper compared to the nominal taper with the majority of measurements at either 0.039 or 0.040 taper.